The invention relates to a valve actuating system having an actuating drive which has a drive housing and an output unit which is movably mounted in the drive housing for generating a stroke of a spindle of a valve for opening or closing a through-flow opening of the valve, wherein the output unit has a force pickup portion to which the spindle is coupleable or coupled and a fastening portion arranged opposite the force pickup portion, wherein the actuating drive furthermore possesses a holder, which is separate from the output unit, has a holder longitudinal-axis and has a fastening device by way of which it is fastened to the fastening portion of the output unit and a support device for supporting at least one position information element on the holder, and wherein the actuating drive comprises at least one position information element.
A valve actuating system of the type mentioned at the outset is known for example from U.S. Pat. No. 6,135,147. The valve actuating system disclosed therein possesses a checking and monitoring device for checking and monitoring the position of a valve element of a valve. The checking and monitoring device can be fastened to the upper end of a valve shaft by way of an ISO or NAMUR interface. The checking and monitoring device possesses a housing, in the circumferential wall of which openings are formed, which are orientated offset from one another in the circumferential direction and in which magnets are inserted in each case. The magnets correspond to associated proximity switches, whereby it is possible to detect the position of the valve element by way of the movement of the valve rod and the proximity of the magnets to the associated proximity switch. Mechanical display means are furthermore provided for visually displaying the position of the valve shaft.
A valve actuating system of the type mentioned at the outset is furthermore known from EP 2 341 270 B1. A rotary drive is provided, having a rotating shaft on the upper end of which a position detecting device is arranged for detecting the position of the shaft. A magnet, which cooperates with a stationary magneto-resistive sensor, is arranged on the shaft, whereby the angular position of the rotating shaft can be detected. A mechanical display is furthermore provided, which is likewise mounted at the upper end of the shaft and therefore rotates together with the shaft. The mechanical position display and the electric position display and magneto-resistive sensor are incorporated together.